package com.zz.parkingsystem.util;

import java.security.MessageDigest;

public class MD5Util {

    /**
     * 将字节转为16进制
     */
    private static String byteArrayToHexString(byte[] b) {
        StringBuilder resultSb = new StringBuilder();
        for (byte value : b) {resultSb.append(byteToHexString(value));}

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    public static String MD5Encode(String origin,String salt, String charsetName) {
        String resultString = null;
        try {
            resultString = salt+origin+salt;
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetName == null || "".equals(charsetName)) {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            }
            else {
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetName)));
            }
        } catch (Exception ignored) {}
        return resultString;
    }

    public static String MD5Encode(String origin, String charsetName) {
        String resultString = null;
        try {
            resultString = origin;
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetName == null || "".equals(charsetName)){
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes()));}
            else{
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes(charsetName)));}
        } catch (Exception ignored) {
        }
        return resultString;
    }

    private static final String[] hexDigits = {"0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};
}
